Some aspects of air pollution - a public health hazard in Czechoslovakia: inter-regional symposium on criteria for air quality and methods of measurement, Geneva, 6-12 August 1963

WORLD HEALTH ORGANIZATION ORGANISATION MONDIALE DE LA SANTE INTER-REGIONAL SYMPOSIUM ON CRITERIA FOR , , .L-._U.· -... ~ Am QUALITY AND METHODS OF MEASUREMENT li'v ,, C~\. • -- if• • • CO I Geneva, 6-12 August 1963 \ ? H or.l ;~;~- : t.\ ' • ~~ ~ / -·· ., 'Y~ ' ··"' '"'"' I ' .,-,. -· .. :_,·~" iil~-.;-11• .. 1'.fHo/ AP I 13 J/ 24 July 1963 ORIGINAL: ENGLISH SG1E ASPECTS OF AIR POLLUTION - A PUBLIC HEALTH HAZARD IN CZECHOSLOVAKIA by Professor K. Symon Director, Institute of Hygiene, Prague In Czechoslovakia, air pollution is a very grave health problem. I already had an opportunity to speak about it at the Symposium on Epidemiological Aspects of Air Pollution organized by the WHO Regional Office for Europe in Copenhagen in December * 1960. The problem is most pressing in industrial areas with open-cast mines, iron works, chemical plants and, of course, in the surroundings of large power plants. There are areas where the concentrations of smoke, grit and dust reach values of several thousands of tons per square meter per year; the values for the oxides of sulfur (especially so2 ) amount to (and sometimes exceed) 1-5 mg/m 3 . Recently in the surroundings of an old-style power station with low chimneys, the concentration of so2 amounted to 40 mg/m 3 • It pro~oked severe disease in tens of persons working in an industrial plant in the vicinity of the power station. It is evident that in the environs of chemical plants, the atmosphere also contains various other pollutants, such as chlorine, fluorine, oxides of nitrogen, hydrogen sulfide, carbon disulfide etc. In the neighbourhood of a power plant using coal containing arsenic, traces of arsenic can be found in the whole environment (air, soil and water). Our Government naturally takes energetic measures to reduce air pollution to the minimum. The large sources of air pollution have been classified in a special list, according to which they already are or will be provided with various types of dust and smoke separators. In some cases extensive reconstruction of industrial * See EUR0-114.2/11 Rev.l AP/l) page 2 plants with the introduction of new techniques is carried out, in order to·de- crease or eliminate the discharge of pollutants (particularly chemical a~d ~etal­ lurgical plants). But the problem of so2 separation remains unsolved particularly because some of our coal contains a considerable amount of sulfur and because new power stations of high capacity (several hundred MW) are being and will be built in densely populated areas. This situation has induced us to study the influence of air pollution o~ the health of the inhabitants. Above all, we began to foll-ow up the children for whom other harmful effects, e.g. the working atmospherej can be excluded. We have shown that in areas with high concentrations of smoke and grit in the atmos- phere, children are somewhat retarded in growth compared with the group of con- trols living in a relatively clean atmosphere, both groups having similar levels of hygiene and similar social and economic condi~ions (climate, housing, diet). We found significant changes in the red blood-cell counts. The erythrocyte counts being very similar, the haemoglobin values and consequently also the colour in- dices differed considerably. In the areas with high concentrations of smoke and grit in the air, these values were statistically significantly lowe~. The values ascertained were also in an evident and statistically significant dependence on the concentration of smoke and grit in the atmosphere. It must be stressed that the children observed lived under similar social and economic conditions. While in areas where dietary deficiencies are prevalent (particularly of proteins) a higher incidence of an~emia of the hyperchromic and macrocytic type can be found, in areas polluted with'smoke and grit anaemias of hypochromic and rather micro- cytic character are found. We have also found higher alkaline phosphatasic values as a result of lack of sunlight and in consequence of ultra-violet radiation, as well as changes in the blbod proteins - relatively higher values of the globulins. This is a concise survey of the results I reported to the Copenhagen Sympo- sium. Since that time we have been able to test our original findings in more than 20 groups of children from different regions, with similar results. We have also succeeded in demonstrating that a stay of from one to three months ih a clean atmosphere has very favourable effects on the children, especially on the haemo- globin, and that this reaction still holds good for about three months after the children return to the original polluted atmosphere. For this reason, in areas where we have not yet succeeded in reducing air pollution, we try to send the children in the course of the year to the so-called open-air schools, where the air is clean. .,;A:P/13 pn.ge 3 As mentioned above, there are in Czechoslovakia n.lso areas with high concen- trations of so2, e.g. the region in the North of Bohemia with open-cast mines of brown coal with a considerably high content of sulfur, and with many large power stations. The concentration of so2 is often more than ten times the maximum per-3 . missible concentration (1.5 mg/m ). vfuen, in this region~ we began to examine the red-blood pictures, we were surprised to find relatively high C'l"'.Y throcyte r;ounts the children. A detailed examination also revealed n majority of microcytes. In figures 1, 2, 3 and 4, four groups of children nre compared - two living in a clean atmosphere in Libechov and Duba, and two in ~n atmosphere with a high con- centration of so2 in Kopisty and Litvinov. In the summation curves the n->ythrocyte counts, average volume of single erythrocytes (in p3), haemoglobin and colour index arc presented. In areas with higher concentrations of so2 in the atmos- phere the children have higher e~:"y-throcy'l.c· <:c1tmt:::;, Hi th :1. smaller volume . (microcytes) and a lower colour index, the level of haemoglobin being practically the same. Figure 5 shows the significance of the differences at the 5% level of significance. In adults no such differences were found, or they were not so sig- nificant. This shows that the organism of the cl1ild rcspcnds to the elevated concentra- tion of so2 similarly as to rather lower oxygen pressure, e.g. in hic;h i~lr:untains. In the resulting polyglobulism and microcytosis, haemoglobin is divided into a greater number of erythrocytes and the organism increases in this way the total surface of the erythrocytes. This makes the transfer of the elevated amount of oxygen to the tissues easier, without intensification of the circulation speed. Perhaps a further investigation will reveal whether this protective mechanism is an innocuous response which ensures the needs of the growing organism, or if it presages anoth(;rhazard. It is also interesting to note that in the groups of children in the clean atmosphere and in that polluted vdth so2, the vitamin-C level in scrum differed considerably, the ~vernge saturation with this vitamin beir~ relatively the same - in the polluted area the values were even higher by half. I believe that these results demonstrate very forcibly the action of the air pollutants and that they can enable us to understand the mechanism of the action as well as of the responses of the organism. It is beyond dispute that we have tried and always will try to kJep noxious substances down to the minimum, or to prevent their emerging at all. But it is clear, too, that for a long time to come, we shall not be successful and it will be necessary, in certain AP/13 page 4 situations to think of other methods for protecting the health of the population, e.g. by strengthening the protective capacities of the human organism. Perfect knowledge of the mechanism of the action of different noxious substances and com- binations of them will make this possible. Also constant experiments with animals will contribute to this knowledge. Some of our results from such experiments con- firm the observations made on children (effect on the red-Cell count, vitamin· C level, alkaline phosphatasis, titre of antibodies to foreign protein, etc.). Other results have focussed our attention on other types of action in the organism - in one experiment so2 provoked a reduction in the values of transaminascs of the type G-0 (i.e. glutamic acid and oxalacctic acid). It shows that there are many gaps in our knowledge about the mode of action of so2 (and other toxic substances) in the organism. The quantitative relationship between the amount of a toxic substance and the response of the organism is also interesting. The extent of air pollution is ascertained by a number of physical and chemical measurements, but we know that the data obtained do not always give an exact picture of reality. The so-called exposition .tests now commonly used in industrial hygi0ne should be applied also to our work •. Physical and chemical measurements of the atmosphere completed with data from various haematological and biochemical tests would yield a more exact picture of the health of the-population in the affected areas. In Czechoslovakia we naturally do not neglect longitudinal investiGations of the morbidity in various polluted areas. We beg~n with a systematic study of the relationship between the presence ,jf carcinogenic substances in the atmos- phere and the incidence of bronchogenic carcinoma in several towns. It is not yet possible to present any results, as the investigations have only been in progress for a short time. In the areas affected, we arc beginning to investigate the so- called osseous age of the children, on the basis of X-ray pictures of the left wrist. For the time being, we have found a relative retardation in the matura- tion of bones, the values of stature growth being the same. Next year we intend to study groups of children in two communities where the atmosphere contains a mixture of the oxides of sulfur and of nitrogen and where, besides other indica- tors, we also find elevated levels of methaemoglobin. At the same time long-term experiments will also be carried out in animals. Similarly, we want to investi- gate areas affected with arsenic. This is a concise survey of some of the results and of the direction of our work. eo 70 60 50 40 20 10 FIG. 1 CUMMULAT lYE CURVES ER Y- Red blood eels number 0~~~--L--L~~~-L--L-~~--L--L~~~~--L--L~--~--J 5 500 thousand 4 OOD '000 WHO 352'+ " FIG. 2 CUMMULATIVE CURVES Single ER Y volume I ~3 I 100r---~--~--~--~----r---,-~~--~--~~~.=~~ , ,.,,'-- ;"' . 90 80 70 60 50 40 :o . I l / I I G I ,1 I ·: I 1: I j! I i.··· .l. I .. ,c?l I ~'I .. :i .:;-, ,:1 'VI I ... ~ ' :; .). 0:. 0 I ·~ '§ :1 ..r:: I ~ Q /· ~ I ~ i!~ I ti-..J I !j I fi I fj ~ .. ~~ /! . : I ... / . . ~· ;· 0~--~---L--~--~~--~--~--_.--~--------- ' 76 79 82 85 88 91 94 ,., 100 10, p WHO 3525 70 60 50 40 20 10 0 10 ., • FIG. 3 CUMMULATIVE CURVES Haemoglobin I!J " 101 * lOT 110 % Hb/100%= 15.6 g% WHO 3526 • " FIG. 4 CUMMULATIVE CURVES Colour index U»~--~~~~~~~~---,---,--~~~--~~~ ,.,. .. ·· ,. "' ,:.~··-· -"' , .... ,.- ,· / ~ . ~ ~ I . , . l , !l /' .!' ~, /i ~ 11 :0°/i~ ,:,/'(1 ·71 Q .. lliiJ ..... lj~ I I j..J I i . I . I I / i I I i I I • I / / I .I I I / i I / i / ,. 60 lO 10 0~~--~--~~~~~--~--~--~--~--~---J 0,81 O,M o,al o,• o,e O,tl o,, 1,• 1,01 1,oe 1,11 %Cl WHO 3527 FIG. 5 SIGNIFICANCE ON THE 5% LEVEL MULTIPLE OF THE VALUES OF THE LEVEL OF SIGNIFICANCE/ OVERPASS OF THE LEVEL OF SIGNIFICANCE IN THE UNITS OF THE VALUES OF THIS LEVEL/ Ery Single Ery volume I )13! Haemoglobin Colour index Kopisty Kopisty Kopisty Litvlnov Litvlnov compared with Litvlnov L ihechov Dubci L 1bechov Dubci 5% level of the significance L ib~chov Dub a WHO 3528